Process of desulfurizing oil or distillate.



UNITED STATES Patented July 5, 1904.

OTTO P. AMEND, OFNEVV YORK, N. Y.

PROCESS OF DESULFURIZING OIL OR DISTILLATE.

SPECIFICATION forming part of Letters Patent No. 764,099, dated July 5, 1904.

Application filed February 25, 1903.

To all whom it may concern.-

Beitknown that I, OTTO P. AMEND, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Processes of Dosulfurizing Oils or Distillates, of which the following is a specilication.

My invention relates to the desulfurization of all sulfur-bearing oils, but especially to the heavier grades of petroleum-oil used for lu bricating purposes.

Hitherto much difficulty has been experienced in desulfurizing the heavy distillate from which lubricating-oils are made. This is especially true of Ohio, Texas, and California oils. I have found that these heavy oils and distillates can be desulfurized as easily as the naphthas and burning-oil, and to accomplish this I utilize a part of the process described in the application for Letters Patent filed simultaneously herewith, Serial No. M5372, particularly that part of it which describes the use of a solution made with a soluble copper salt; but as the faintest trace of acid in a lubricating-oil is a fatal defect and as the presence of caustic in any material quantity is also objectionable, and, further, as it is desirable to remove as much as possible of the copper employed to effect desulfurization it becomes imperative either to substitute an after treatment to effect the removal of the copper held in suspension in the oil in lieu of the acid treatment used in application Serial No. M21072 or to redistil it. I prefer to use the after treatment hereinafter described, which may also be used to advantage with lighter oils, to which the ordinary acid treatment may be subsequently employed for further reiinement.

In the desulfurization of heavy distillates I have found that in the presence of neutral saline solutions hydrates of the metals, especially hydrate of copper, will readily combine with sulfur of the sulfur compounds in the oils or distillates referred to, the latter forming hydrosuliid of copper, which precipitates and which may be easily separated from the oil or distillate so treated, and after such separation it can be shown that the oil or distillate Serial No. 145,073. (No specimens.)

.plumbate of soda, mercury, or with any of the well-known means employed to indicate sulfur reaction in oils.

In carrying out my invention I proceed as follows: I first wash the oil or distillate and blow it well with air, steam, or with both to remove as much sulfureted hydrogen as possible. I then remove the wash-water and add enough caustic solution (preferably causticsoda solution, as it is the cheapest) to neutraliZeTlie organic acids found in portions of the distillate. I usually employ of the solution about one per cent. of the weight of oil, the solution containing from three to five per cent. of caustic soda. After thorough agitation the caustic soda is drawn ofli, and with it more or less coloring matter separated or taken up by it. I then apply an aqueous solution of a soluble salt of copper in quantity about five per cent. of the weightof the oil or distillate and preferably one of 25 Baum strength. The sulfate being the cheapestI employ it. After agitating the oil or distillate with the copper solution I add of caustic-soda or potash solution of 25 Baum strength onehalf of one per cent. of the weight of the distillate. The addition of this caustic solution gives a freshly-precipitated hydrate of copper and, with an excess of copper present, the resulting sulfate of the alkali. The hydrated copper combining with the sulfur in the dis tillate forms hydrosulfid of copper, which with the sulfate of the alkali settles to the bottom of the'oil or distillate and is removed. After such removal the oil or distillate is thoroughly washed with water and then when well settled and the water is drawn off it is agitated in contact with ferrous hydrate in a neutral solution of ferrous sulfatesay about five per cent, by weight, of the distillate treated and of about 25 Baum strengthby means of a strong currentof air or air and steam, the air being introduced therein by a pump or blower and communicating pipes or by any suitable mechanical device adapted to the purpose.

The ferrous hydrate is produced by adding to the ferrous sulfate solution about onequarter of one per cent. of caustic-soda solution of five per cent. strength, which also neu- IOU tralizes any trace of acid that may be present in the ferrous-sulfate solution, thereby insuring a neutral ferrous solution.

The hydrate-of-iron and neutral iron solutions readily take up oxygen from the air or steam and acting as powerful oxidizing agents convert the insoluble hydrosulfid of copper into a soluble sulfate of copper. This may easily be detected by the change of color. The sulfate-of-copper and the iron solutions are then drawn off, and after a thorough washing the oil is allowed to settle or is filtered. It is then ready for use. 1 have used manganates and chromatcs to make the neutral solution; but I prefer the ferrous sulfate, as it is cheaper and just as effective.

It will be observed that the quantity of sa: line copper solution used to effect desulfurization is largely in excess of the quantity of caustic and that while the quantity of caustic employed is sufiicient to neutralize any acid present and to. effect a partial precipitation of the copper there remains an excess of neutral saline copper solution. Therefore the action of the caustic must be to first neutralize the acid present, if there should be any, and then to effect a partial precipitation of freshly-hydrated copper and the resulting sulfate of the alkali applied, thereby producing of necessity a neutral saline solution, which in consequence of its specific gravity separates quickly from the oil or distillate after agitation ceases.

I am aware that distillatcs have been treated with copper and copper salts with an excess of acid and with an excess of alkali, but have found in both cases that the product so ob tained was so saturated with copper that it was impossible to remove it with any ordinary acid and alkali treatment and that the presence of copper in the oil deprives it of value. I am also aware that hydrated copper has been used in the presence of heat; but it is well known that hydrated copper plus heat produces an oxid of copper plus water, as the fol.- lowing formula will show:

Cu(O.H)2+ heat GuO+H2O,

and the heat reaction so combines the copper with the oil as to render it inseparable except by rediistillation.

The use of hydrated: copper in a neutral solution, as described in this application, makes it possible to dcsulfurize the distillate without combining copper with it, and what copper is. taken up or held: in suspension is insoluble in sulfuric acid. and can be readily eliminated by the method employed in application Serial No. 145,072 or by the method herein described for lubricating-oils.

I do not confine myself to the use of concentrated solutions of sulfate of copper and alkali, as very dilute solutions of the reagents specified if used in sufficient quantity will satisfactorily desulfurize the distillatcs, the allimportant part being the use of a quantity of the copper and iron solutions in excess of the alkali solutions and sufficiently so to produce neutral saline solutions, as described. I prefer the concentrated solutions, for the reason that it is easier to separate and remove them from the oil or distillate.

This process, as described, has been applied to the desulfurization of Ohio, Canadian, and Texas sulfur-bearing oils; but the most difficult samples encountered and successfully refined have been samples of thirty per cent. straightrun plus thirty per cent. more of cracked Findlay, Ohio, oil, making sixty per cent. of the same distillation.

Having described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. The process of desulfurizing oil or distillate which consists: in removing the sulfurcted hydrogen and neutralizing the fatty and organic acids contained therein; then in exposing the oil or distillate with its sulfur or sulfur compounds to the action of a soluble salt of copper in the presence of an alkali; in removing the excess of copper and copper hydrosulfids and exposing the oil or distillate and any hydrosuliid of copper remaining therein, tov the oxidizing effect of one or more oxidizing agents; in removing the resulting copper sulfates and settling the oil, all substantially as described.

2. The process of desulfurizing oil or distillate which consists: in neutralizing organic acids contained therein; in exposing the oil or distillate to the action of a soluble salt of copper in the presence of an alkali in a neutral saline solution; in removing the excess of copper and copper hydrosuliids and exposing the oil or distillate and any hydrosuliid of copper remaining therein to the oxidizing action of one or more oxidizing agents; in removing the resulting copper sulfates and settling the oil or distillate.

3. The process of desulfurizing oil or distillate which consists: in neutralizing the acid contained therein; in exposing the oil or distillate to. the action of a copper hydrate in a neutral saline solution; in removing the excess of copper and copper hydrosulfids and exposing the oil or distillate and any hydrosulfid: of copper remaining therein to the oxidizing action of one or more oxidizing agents; in retling the oil or distillate, all substantially as described.

5. The process of desulfurizing oil or distillate which consists: in exposing them or either of them with the sulfur or sulfur compounds therein contained, to the action of a copper hydrate in a neutral saline solution; in exposing the resulting copper hydrosulfids to the oxidizing action of one or more oxidizing agents; in removing the resulting copper sulfate and settling the oil, all substantially as described.

6. The process of desulfurizing oil or distillate which consists: in exposing them or either of them to the action of a copper hydrate in a neutral saline solution, then exposing the oil or distillate with the resulting copper hydrosulfids to the action of ferrous hydrate and a current of air; in removing the resulting copper sulfate and settling the oil or distillate, all substantially as set forth.

7 The process of desulfurizing oil or distillate Which consists: in exposing them or either of them to the action of a copper hydrate in a neutral saline solution and then exposing the resulting copper hydrosulfids in the oil or distillate to the action of ferrous hydrate and an injection of steam; in removing the resulting copper sulfate and settling the oil or distillate all substantially as set forth.

8. The process of desulfurizing oil or distillate Which consists: in exposing them or either of them to the action of a copper hydrate in a neutral saline solution and then exposing the resulting copper hydrosulfids to the action of ferrous hydrate a neutral solution of ferrous sulfate and a current of air and steam; in removing the resulting copper sulfate and set tling the oil or distillate, all substantially as set forth.

9. The process of desulfurizing oil or distillate Which consists: in neutralizing the acid contained therein by exposure to an alkali and then exposing the oil or distillate with the sulfur or sulfur compounds therein contained to the action of copper hydrate in a neutral saline solution thereby forming copper hydrosulfid; in oxidizing the copper hydrosullids by exposing them to the action of ferrous hydrate, a neutral solution of ferrous sulfate and a current of air or steam converting the insoluble copper sulfid into a soluble copper sulfate; in removing the resulting copper sulfate and settling the oil or distallate, all substantially as set forth.

10. The process of desulfurizing oil or distillate Which consists: in exposing the sulfur and sulfur compounds therein contained to the action of copper hydrate and then subjecting the resulting copper sulfids to the action of one or more oxidizing agents as ferrous sulfate and air or steam, substantially as described.

11. The process of desulfurizing oil or distillate which consists: in so treating the oil or distillate as to insure therein an alkaline reaction and then exposing the alkaline oil or distillate to the action of a soluble salt of copper, as sulfate of copper; in removing the excess of copper and copper hydrosullids, substantially as set forth.

OTTO P. AMEND.

WVitnesses:

JACOB B. Toon, FREDERICK C. H. LANGE. 

